Find My iPhone Email Notification
Solution 1:
The email feature while using Find My iPhone has been there for a very long time. The email notification feature was silently added as a feature way back in 2011. The email is sent sent when the device reconnects to a network.
There aren't options to turn this feature off.
Solution 2:
There is a flurry of the "Find my phone" issues today.
I would assume it is a problem with Apple servers.
I would suggest you turn the Find my phone off, wait for 1/2 hour and turn it on again (to reset).
Also it might be a bug in the iOS 8.01 so for now just disable it.
Turn off "Find My iPhone" on your phone if you're using the feature. You can do this under Settings > iCloud > Find My iPhone.